Last updated date: 11-Mar-2024

Medically Reviewed By

Medically reviewed by

Dr. Lavrinenko Oleg

Originally Written in English

Everything you need to know about Impetigo

    What is Impetigo?

    Impetigo is the most common bacterial skin infection in children between the ages of 2 and 5. There are two main types: non-bullous (70% of cases) and bullous (30% of cases). Non-bullous impetigo or infectious impetigo is caused by Staphylococcus aureus or Streptococcus pyogenes and is characterized by honey-coloured crusts on the face and extremities. Impetigo primarily affects the skin or it may be secondary to insect bites, eczema, or herpes lesions. Bullous impetigo, only caused by S. Staphylococcus aureus produces large, loose blisters and is more likely to involve the abraded area. These two types usually subside within two to three weeks without leaving a scar. Complications are rare, the most serious is glomerulonephritis after streptococcal infection.

    In the United States, more than 11 million skin and soft tissue infections are caused by Staphylococcus aureus each year. Impetigo is the most common skin infection in children between the ages of 2 and 5, but it can affect people of any age. One third of skin and soft tissue infections in returning passengers can be attributed to impetigo, usually secondary to the bite of an infected mosquito. Many bacteria inhabit healthy skin; some types, such as S. Suppurative and Staphylococcus aureus intermittently colonize the nose, axilla, pharynx, or perineum area. These bacteria can cause susceptible skin infections. Other factors prone to impetigo are skin trauma, hot and humid climate, poor sanitation, crowded places, malnutrition and diabetes or other comorbidities. Autologous vaccination via fingers, towels, or clothing usually results in satellite lesions in the adjacent area. The highly contagious nature of impetigo also allows patients to spread to their close contacts. Although impetigo is considered a self-limiting infection, antibiotic treatment is usually started to cure faster and prevent spread to others. This helps to reduce absenteeism from working days. Hygiene habits, such as cleaning minor injuries with soap and water, washing hands, bathing regularly, and avoiding contact with infected children can help prevent infection.

    Impetigo is a bacterial skin infection, most commonly seen in young children.


    Types of Impetigo

    Impetigo is a skin infection caused by one or two of the following bacteria: group A streptococcus and Staphylococcus aureus. In addition to impetigo, group A streptococci can cause many other types of infections. When group A streptococci infect the skin, it can cause ulcers. If someone comes into contact with these sores or the fluid in the sores, the bacteria will spread to other people.

    Anyone can get impetigo, but certain factors can increase someone's risk of this infection.

    Impetigo has two manifestations: non-bullous (also called contagious impetigo) and bullous.

    • Non-Bullous impetigo. Non-bullous impetigo is the most common manifestation, accounting for 70% of cases. Non-bullous impetigo can be divided into more common primary or secondary (common) forms. Primary impetigo is a direct bacterial invasion of intact healthy skin. Secondary (common) impetigo is a bacterial infection of injured skin caused by trauma, eczema, insect bites, scabies, or outbreaks of herpes and other diseases. Diabetes or other underlying systemic diseases can also increase susceptibility. Impetigo begins with a maculopapular eruption and develops into thin-walled vesicles that rapidly rupture, leaving a superficial erosion, sometimes itchy or painful, covered by the classic honey-coloured skin. If left untreated, the infection can last two to three weeks. Once the scab is dry, the remaining area will heal without scarring. Exposed skin on the face (e.g., nostrils, perioral area) and extremities are the most commonly affected areas. Regional lymphadenitis may occur, but systemic symptoms are unlikely. Non-bullous impetigo is usually caused by S. Staphylococcus aureus, but Streptococcus pyogenes may also be involved, especially in warm and humid climates.


    • Bullous impetigo. Bullous impetigo is caused only by Staphylococcus aureus. It is characterized by large, fragile, loose blisters that may rupture and ooze a yellow fluid. It usually clears up in two to three weeks without scarring. After rupture of the bulla, characteristic scales will form on its periphery, leaving a fine brown crust on the remaining erosion. These larger blisters are formed by exfoliative toxins produced by strains of Staphylococcus aureus that cause loss of adhesion of the epidermal cells. Bullous impetigo is usually seen on the trunk, armpits, and extremities, and in the area of ??the intertrigo (diaper). 2 is the most common cause of sore rash on the buttocks in babies. Systemic symptoms are not common, but can include fever, diarrhoea, and weakness.


    Signs and Symptoms

    The impetigo starts as a red, itchy sore. When it heals, yellowish or "honey-coloured" crusts will form on the sores. Generally speaking, impetigo is a mild infection that can occur anywhere in the body. It most often affects exposed skin, such as around the nose and mouth or the arms or legs. Symptoms include red, itchy sores that break open and ooze clear fluid or pus for several days. A yellow or "honey-coloured" crust then forms on the sore, which then heals without leaving a scar. It usually takes 10 days for someone to develop sores after being exposed to group A streptococci.


    Risk factors for Impetigo

    Close contact with another patient with impetigo is the most common risk factor for disease. For example, if someone has impetigo, he usually spreads it to other people in the family. Infectious diseases also tend to spread in places where large numbers of people gather. Crowded environments, such as schools can increase the spread of impetigo. Impetigo is most common in areas with hot and humid summers, mild winters (subtropical), or wet and dry seasons (tropical), but it can occur anywhere. Lack of proper hand washing, bathing, and facial cleansing can increase the risk of impetigo.

    Impetigo is most common in children between 2 and 5 years of age. People infected with scabies have an increased risk of impetigo. Participating in activities that frequently cut or scrape can also increase the risk of impetigo.


    Complications of Impetigo

    Serious complications are very rare. Kidney problems (glomerulonephritis after strep infection) can be a complication of impetigo. If someone has this complication, it usually begins a week or two after the skin ulcer disappears.


    Diagnosing Impetigo

    Doctors usually diagnose impetigo by observing the sore (physical examination). No laboratory testing is required. Bacterial culture and antibiogram are recommended to determine possible methicillin-resistant Staphylococcus aureus (MRSA), if an impetigo flare occurs, or if there is a streptococcal infection followed by glomerulonephritis. In individuals with suspected acute post-streptococcal glomerulonephritis (APSGN), evidence of past streptococcal skin infections may be found.

    For patients with non-aggressive lesions, after removing the honey-coloured scabs and lifting the scabs, a fresh exudate bacterial culture can be obtained under the scabs. For patients with bullous lesions, Gram's stain and fluid culture from the bullae is performed. On Gram stain, the presence of Streptococcus gram-positive cocci indicates Streptococcus pyogenes; groups of gram-positive cocci indicate Staphylococcus aureus. Culture results and antibiograms can help doctors choose the appropriate antibiotic treatment.

    More than 92% of patients with impetigo-related APSGN have elevated anti-DNase B titers. Patients with impetigo have a poor antistreptolysin O (ASO) serologic response; only 51% of patients with impetigo-related APSGN have elevated ASO titers. If the patient develops new edema or hypertension, a urinalysis is required to evaluate APSGN. The presence of hematuria, proteinuria, and tubular cells in the urine are indicators of kidney involvement. 

    Potassium hydroxide wet tablets can rule out a bullous dermatophyte infection. A Tzanck preparation or virus culture can be done to rule out a herpes simplex infection. Bacterial cultures can be obtained from the nasal passages to determine if the patient is a carrier of Staphylococcus aureus. If the nasal cavity culture is negative and the patient continues to have impetigo that is recurring, bacterial culture of the armpits, pharynx, and perineum should be performed.

    Serum IgM levels are obtained in the case of recurrent impetigo in patients with negative Staphylococcus aureus carrier status and no pre-existing susceptibility factors such as skin diseases. The serum levels of IgA, IgM and IgG, including the subclasses of IgG, need to be determined to rule out other immunodeficiencies.


    Treatment of Impetigo

    Treatment of impetigo

    Impetigo is treated with antibiotics, which are applied to the sore (topical antibiotics) or taken by mouth (oral antibiotics). Your doctor may recommend a topical ointment, such as mupirocin or fusidic acid, that is only used to treat a few sores. When there are more sores, oral antibiotics can be used.

    Treatment includes topical antibiotics such as mupirocin, retamoline, and fusidic acid. Oral antibiotic therapy can be used for impetigo with large blisters or when local treatment is impractical.

    Amoxicillin/clavulanic acid, dicloxacillin, cephalexin, clindamycin, doxycycline, minocycline, trimethoprim/sulfamethoxazole and macrolides are a few options, whereas penicillin alone is not. It is rumoured that those natural remedies like tea tree oil; olive oil, garlic and coconut oil; and manuka honey are successful, but there is insufficient evidence to recommend or reject them as treatment options. Treatments in development include minocycline foam and ozenoxacin, a topical quinolone drug. Local disinfectants are inferior to antibiotics and should not be used alone. Empirical treatment is considered to change with the increasing prevalence of antibiotic-resistant bacteria. Methicillin-resistant Staphylococcus aureus, macrolide-resistant Streptococcus, and mupirocin-resistant Streptococcus have been documented. Fusidic acid, mupirocin, and retamoline cover methicillin-sensitive Streptococcus and Staphylococcus aureus infections. Clindamycin helps in suspected methicillin-resistant Staphylococcus aureus infections. Trimethoprim/sulfamethoxazole covers S. Staphylococcus aureus infection, but not sufficient for streptococcal infection. 

    Topical antibiotics are more effective than placebo and are better than oral antibiotics for localized impetigo. Oral penicillin should not be used for impetigo because it is not as effective as other antibiotics. Due to the development of drug resistance, oral erythromycin and macrolides should not be used to treat impetigo. There is insufficient evidence to recommend the use of topical disinfectants to treat impetigo. There is insufficient evidence to recommend (or rule out) popular herbal treatments for impetigo. Antibiotics can also help protect other people from getting sick.


    Protecting yourself and others

    People may have impetigo more than once. Having impetigo does not protect someone from being infected again in the future. Although there is no vaccine to prevent impetigo, people can take steps to protect themselves and others.


    How to take care of Impetigo wounds?

    Cover impetigo to help prevent the spread of group A streptococci to others. If you have scabies, treating the infection can also help prevent impetigo. Good wound care is the best way to prevent bacterial skin infections (including impetigo):

    • Use soap and water to clean all small wounds and injuries (such as blisters and abrasions) that cause the rupture of the skin.
    • Clean and cover wounds with a clean, dry bandage until healed.
    • See a doctor for a puncture and other deep or serious wounds.

    If you have open wounds or active infections, avoid:

    • Jacuzzis;
    • Swimming pools;
    • Natural bodies of water (for example, lakes, rivers, oceans).




    Proper personal hygiene and regular washing of body and hair with soap. The best way to prevent infection or the spread of group A strep is to wash your hands frequently. This is especially important after coughing or sneezing. To prevent group A streptococcal infection, you should:

    • Cover your mouth and nose with a tissue when you cough or sneeze.
    • Throw the used tissues into the trash can.
    • When coughing or sneezing, if you do not have a tissue, please face your upper sleeve or elbow instead of your hand.
    • Wash your hands often with soap and water for at least 20 seconds.
    • If soap and water are not available, use alcohol-based hand sanitizer.
    • The clothes, bedding, and towels of patients with impetigo must be washed every day. These items should not be shared with anyone else. Once cleaned, these items can be safely used by others.

    People diagnosed with impetigo can return to work, school or nursery if:

    • They have started antibiotic treatment
    • They cover all exposed skin sores
    • Use the prescription exactly as directed by the doctor.
    • Once the sore has healed, people with impetigo generally cannot pass the bacteria to other people.


    Lifestyle and Home Remedies

    For minor infections that have not spread to other areas, you can try over-the-counter antibiotic creams or ointments to treat the sores. Placing a non-stick bandage on this area can help prevent the sore from spreading. Avoid sharing contagious personal items, such as towels or sports equipment.


    Preparing for your appointment

    When you call your doctor or your child's pediatrician to make an appointment, ask if you need to take any steps to prevent infection from others in the waiting room.

    Please list the following to prepare for your appointment:

    • Symptoms you or your child are experiencing
    • All medications, vitamins and supplements that you or your child are taking
    • Key medical information, including others situation

    Questions to ask your doctor

    • What can cause ulcers?
    • Do I need to do a test to confirm the diagnosis?
    • What is the best practice?
    • What can I do to prevent the spread of an infection?
    • During the recovery period, what skin care routines do you recommend for me?

    In addition to the questions you are going to ask the doctor, you can ask other questions at any time during the appointment.

    What to expect from your doctor

    Your doctor may ask you a series of questions, such as:

    • When did the sore start?
    • How was the sore at the beginning?
    • Have you had cuts, scrapes, or insect bites in the affected area recently?
    • Is the sore or itchy?
    • Does anyone in your family already have impetigo?
    • Has this problem occurred before?


    Impetigo vs herpes simplex virus (cold sores)

    Herpes simplex virus (HSV) infection is the most commonly mistaken condition for impetigo. To avoid confusion, the Center for Chronic Disease Biology (CBCD) wants to emphasize the difference between herpes simplex virus (HSV1 or HSV2) infection and impetigo, bacterial infection of the skin.

    How do you distinguish?

    The clues to look for include intact vesicles (liquid-filled vesicles that can appear on the skin) If they are intact (intact or watery), the infection is more likely to be HSV. And, over time, if the vesicles become cloudy and become honey-colored scabs, the infection is more likely to be herpes. Lastly, herpes infections often recur. In other words, if a person is infected, they are likely to have more than one outbreak of sores and these sores will turn into blisters. This is not the case with Impetigo. "When a pustular pustule is roofless, it will obviously be filled with pus. A herpetic lesion may appear to be pus-filled, but when drained, only a small amount of clear fluid can be found. Lastly, antibiotics are generally used for impetigo infections, while antiviral medications are generally used for herpes infections.


    Is it Impetigo or another Skin condition?

    Skin conditions that cause sores, blisters, and scabs can sometimes be itchy. Impetigo is no exception, and some children and adults experience itchiness. But with impetigo, the itching is usually mild, and some people don't feel any itch at all. On the other hand, rashes caused by allergic reactions, such as poison ivy, may continue to itch and will not improve until a topical anti-itch cream is applied. Scabies, a highly contagious skin disease caused by mites that hide under the skin, can cause an impetigo-like rash. But scabies can cause severe and severe itching all over the body, usually worse at night, most commonly on the hands, forearms, and genitals. Ringworm can also itch, but the appearance of this rash is different from impetigo. In addition to the small bumps on the skin, ringworm also has a raised border around the scaly patches of the skin.

    You can mistake chickenpox for impetigo. This infection also has small, itchy, fluid-filled blisters. But similar to scabies, chickenpox can cause severe itching. The itching can also be accompanied by other symptoms. These include fever, headache, and loss of appetite. Fresh (or newer) chickenpox blisters are usually filled with clear fluid in inflamed red round patches, and scabs or oozes are usually not seen in impetigo.

    Impetigo usually lasts only 1 week after antibiotic treatment. Impetigo is also different from other rashes in terms of duration. If treated with antibiotics, impetigo usually disappears in about a week. If allowed to heal on its own, the rash will usually heal within two to four weeks without leaving a scar. Chickenpox lasts for a short time. It clears up on its own too, but it only lasts for 5-10 days. Scabies infection does not go away on its own. You should consult a doctor and use topical medications to kill the mites. The good news is that this medicine works very quickly, and applying a treatment from the neck down is usually enough to kill the mites and their eggs. However, although scabies treatment is quick, the itching can last for several weeks.

    The ringworm rash will improve within two weeks of treatment. Over-the-counter medications are effective, but prescription antifungals are generally required to treat stubborn ringworm. Molluscum contagiosum is a viral infection that is most common in children. Like impetigo, this rash will go away on its own. Unfortunately, these bumps on the skin may take months or even years to disappear. The root cause of impetigo is different from other rashes. Another factor that distinguishes impetigo from other rashes is the root cause. Impetigo is a bacterial skin infection caused by staph or strep. If you or your child is cut, abraded, or bitten by an insect, Staphylococcus or Streptococcus can invade the body and cause a superficial infection of the upper layer of the skin. This cause is different from other rashes. Scabies is caused by mites, while ringworm is caused by fungal infections. Other rashes, such as poison ivy, are caused by allergic reactions. Some sores and rashes are the result of viral infections, such as cold sores and chickenpox.


    Bottom line

    It is essential that you seek medical advice if you suspect you have impetigo or any other skin conditions. Impetigo, although bothersome is easily treatable.